1. Field of the Invention
The present invention relates to a hermetic compressor and a refrigeration cycle device having the same, and particularly, to a hermetic compressor capable of separating oil from a refrigerant discharged from a compression unit and recollecting the oil to the hermetic compressor, and a refrigeration cycle device having the same.
2. Background of the Invention
A compressor is an apparatus for converting mechanical energy into fluid compression energy. A hermetic compressor is provided with a driving motor for generating a driving force, and a compression unit for compressing fluid by receiving the driving force of the driving motor. The driving motor and the compression unit are installed in an inner space of a casing.
In a hermetic compressor for use in a refrigerant compression type refrigeration cycle, a preset amount of oil is stored in the casing so as to cool the driving motor and/or lubricate and seal the compression unit. However, when the hermetic compressor is being driven, refrigerant discharged from the hermetic compressor may be discharged to the refrigeration cycle in a mixed state with oil. And, some of the oil discharged to the refrigeration cycle may remain in the refrigeration cycle without being recollected into the hermetic compressor, resulting in oil deficiency inside the hermetic compressor. This may lower reliability of the hermetic compressor, and the refrigeration cycle may have a lowered heat exchange performance due to the oil remaining therein.
In order to solve these problems, has been proposed an oil recollecting apparatus capable of preventing oil deficiency inside a compressor and maintaining a heat exchange performance by a refrigeration cycle, by separating oil from a refrigerant discharged from an outlet of the compressor by using an oil separator installed at the outlet, and by recollecting the separated oil into an inlet of the compressor. However, the conventional oil recollecting apparatus for a hermetic compressor has the following problems.
First, because an outlet of the conventional oil separator is connected to the inlet of the compressor having a relatively low pressure, not only the oil separated by the oil separator but also the refrigerant may backflow to the inlet of the compressor. This may cause the amount of the refrigerant which circulates in the refrigeration cycle to be deficient, thereby resulting in a low cooling capability of the refrigeration cycle.
Second, because high-temperature oil and refrigerant are sucked to the inlet of the compressor, a suction refrigerant has an increased temperature. This may increase a volume ratio of the refrigerant, and thus the amount of the refrigerant sucked to the compression unit of the compressor is reduced. This may result in a lowered cooling capability of the compressor.
Third, because the oil separated by the oil separator is mixed with a sucked refrigerant thus to be discharged from the compression unit, oil deficiency may occur at the inner space of the casing. This may lower the reliability of the compressor.